need opinion on audio codec

[takeru]

i am encoding large divx5 files, roughly equivalent to 4 hours worth of video with 5.1 channel sound per dvdr disc. question now is, which audio should i use? should i just use the original ac3 file, or should i re-encode it to a 5.1 ogg file? the size is roughly the same when i encode the ogg file. whats optimal bitrate for a 5.1 ogg file anyway?

[DSPguru]

aac

[takeru]

which aac encoder has proper channel mapping though?

[jeremymacmull]

Its easiest if you just keep the AC3 file no reencoding and there would not be much file size difference anyway

[Kent Wang]

AAC is more efficient though... Harder, but higher quality. I'm currently using 2-channel Vorbis for 2-CD film rips and waiting to switch to AAC when HE AAC stabilizes.

[Herske]

Use AAC. Latest Nero encoder has the correct channel mapping.

[Soulhunter]

I would keep the AC3-file...!

Every re-encoding lowers the quality, and it makes no sense to re-encode audio when u save it on DVD-R. Sure, it's another thing for CD-R's... ;)

But I'm still waiting for AAC+... DTS->AAC+ :D :D :D

Bye

[Herske]

Why wait? AAC+ aka HE-AAC is available in Nero since 25th of July.

[takeru]

but i thought only nero player plays out aac+(he-aac) files it produces correctly?

[Hello]

Can AVI be wrapped with AAC? If so, does BeSweet encode with it and come with it? Thanks.

[Hello]

Or how about DTS? Which is considered a higher quality?

[bobsc]

Originally posted by Hello
Can AVI be wrapped with AAC? If so, does BeSweet encode with it and come with it? Thanks.

Yes. For 2 channel you could use AacMachine, for multichannel use Nero or FAAC.

[Soulhunter]

"Or how about DTS? Which is considered a higher quality?"

AFAIK AAC+ gives same quality with lower bitrates...
So, when you convert DTS to AAC you can have DTS quality with a filesize of a DD5.1 file... (I think) Not sure how much better the AAC compression is than the AC3 one... But what Ive heard it works well :D

Bye

[bond]

Originally posted by bobsc
Yes. For 2 channel you could use AacMachine, for multichannel use Nero or FAAC. and why not nero for 2 channels :rolleyes:

Originally posted by Soulhunter
So, when you convert DTS to AAC you can have DTS quality with a filesize of a DD5.1 file... (I think) Not sure how much better the AAC compression is than the AC3 one... But what Ive heard it works wellaac should give a normal user a similar quality like ac3 or dts streams at 128kbps (2 channels)
i dont think that 96kbps is tuned well enough for now...

[bobsc]

Originally posted by bond
and why not nero for 2 channels :rolleyes:

Oh boy, he was asking about BeSweet. :p

[bond]

:p
but aacmachine isnt besweet ;)
and you could have redirected him to the new nero ac3 plugin :D

btw. aac cant be put into .avi without ugly hacks...

[Soulhunter]

@ bond
>
aac should give a normal user a similar quality like ac3 or dts streams at 128kbps (2 channels)
i dont think that 96kbps is tuned well enough for now...
<

So, there's the reasons to wait... ;) :D

Bye

[bond]

Originally posted by Soulhunter
So, I keep on waiting... ;) :Dnah, i would definitely try ogg for multichannel encoding.
i dont have a 5.1 system but i guess that you can get good results with a 5.1 ogg file at ~200kbps (just a guess of course)

if you still want to wait a little bit, wait for better tuning of he-aac in nero!
or even better try it out now (he-aac with the 50-70kbps vbr preset in nero will result in a 200kbps multichannel file i think) and look if you like the results :)

or try both vorbis and he-aac on a sample file and compare them with the original source,
i am sure after a little bit of testing you can get similar quality like ac3 or dts with a considerable lower bitrate

[nuked]

hmmm... doesn't seem like the issue is can you save space, but does it matter? original ac3 for 4 hours is what 800MB, call it a gig. that leaves 3.7(dvd's are what 4.7 gigs right?) gigs for video... which is about 2,155kbps. It's hard to get divx5 to use that high a bit rate if you try except maybe on fullscreen content. So I'll pile on another vote for keeping the ac3.

[takeru]

Originally posted by nuked
hmmm... doesn't seem like the issue is can you save space, but does it matter? original ac3 for 4 hours is what 800MB, call it a gig. that leaves 3.7(dvd's are what 4.7 gigs right?) gigs for video... which is about 2,155kbps. It's hard to get divx5 to use that high a bit rate if you try except maybe on fullscreen content. So I'll pile on another vote for keeping the ac3.

size if a dvd-r is 4.36gig. i use roughly 1700 bitrate to maintain a good amount of quality, but i want to see if i can raise that with a smaller sound file.